Farrell was the captain of the University of Pennsylvania baseball team before signing with the New York Giants prior to the 1925 season. A well-traveled utility, he played with six different teams in a span of nine years, including two stints for the Giants. His most productive season came in 1927, when he posted career-highs with a .316 batting average, 92 RBI, 57 runs, and 152 games while playing three different infield positions for the Giants and Braves, being considered in the National League MVP vote at the end of the season. He played exclusively at shortstop 132 games for the 1928 Braves and also won a World Series ring with the Yankees 1932 World Champions, despite he did not play in the Series.